Tank sampling apparatus



May 27, 1958 T. L. CLiFT TANK SAMPLING APPARATUS Filed May 21, 1954INVENTOR. T/'/f/?L/5 L. CL/FT A T TO 72/VEX5- United States PatentOfiice 2,836,068 Patented May 27, 1958 TANK SAMPLING APPARATUS TherlisL. Clift, Erlanger, Ky., assignor to The Standard Oil Company,Cleveland, Ohio, a corporation of Ohio Application May 21, 1954, SerialNo. 431,555

2 Claims. (Cl. 73-421) With bulk containers, such as tanks, as inpetroleum refineries, or in field installations, etc., it is commonlynecessary to obtain samples of the liquid contents from time to time,and it is desirable that this be accomplished without undueinconvenience. It is also desirable that the attaining of samples beunder such conditions that accurately representative samples of theliquid be obtained. It is further desirable that it be possible toperform sampling operations without waste or spilling on the ground ornecessity of draining into the sewer. In accordance with the presentinvention, such desired standards may be obtained, and in addition itbecomes possible to sample liquids which are in very wide range, both asto composition and specific gravity, and also importantly as totemperature. In this latter respect it thus becomes possible to takesamples of molten materials which if casually handled would solidifysuch as to interfere with handling which is not conducted promptly. Andwithal, the equipment is versatile in its applicability to bulkcontainers of wide range, and involves relatively simple equipment.Other objects and advantages of the invention will appear from thefollowing description.

To the accomplishment of the foregoing and related ends, said invention,then, comprises the features hereinafter fully described andparticularly pointed out in the claims, the following description andthe annexed drawing setting forth in detail certain illustrativeembodiments of the invention, these being indicative, however, of but afew of the various ways in which the principle of the invention may beemployed.

In said annexed drawing:

The sole figure is a perspective view of tank equipment embodying theinvention, a portion being in section to better show detail.

in general, the invention involves a circulatory circuit which in partis within the bulk container or tank, and in part outside, the latterincluding liquid-propelling means and a tap-out for drawing a samplefrom the circuit.

An illustrative embodiment involves a bulk container, an oil tank T,such as in refinery equipment, or in the field, and an inlet pipe 2 andan outlet pipe 3 are in spaced-apart relation and may have their innerends in preferred cases even projecting within the tank for an averagingor representative location back from the tank wall, and also in alocation such as is desired in any particular case above the floorlevel. The outlet pipe 3 connects in closed circuit with the inlet pipe,and interposed is a liquid-propelling means 4 which operates to providea circulation from the end of the inlet pipe to the end of the outletpipe, thus in the tank liquid and thence in the outside portion of thecircuit back to the inlet. This outside piping may be covered withinsulation if desired. While mechanical liquid-propelling means may beused in some cases, it is preferable to apply a Venturi-type means suchas an injector, also sometimes called an eductor, and an illustrativeinstance of which is a Schutte-Koerting Syphon No. 217. This type ofdevice has an advantage in that a gaseous propellant, usually air, or insome rare instances steam, breaks up a dense mass of particularlyviscous liquid material and facilitates its movement. Using air pressureas a propellant force, thus an air pressure supply inlet pipe 8 may havea connection through pipe 5 into the injector or eductor 4, while thereturn circuit from pipe 3 connects into the injector also. In theoutlet pipe 3 a branch 10 with its control valve 11 allows the drawingoff of a desired sample into a sampling vessel S, as desired.

In cases where the air supply contains condensing-out moisture, it isdesirable to include in the line a water collector, such as a receptacle9 to which the air inlet pipe leads and from which the further pipe 5goes to the injector 4.

A set of control valves is required, and valve 13 controls the air inletsupply, while valve 14 is interposed between the water collector and thevent 6, and valve 15 is interposed between the vent and the injector,while valves 16 and 17 are interposed in the inlet and outlet pipeconnections of the tank.

The process of sampling is as follows: Vent valve 7 is closed, andvalves 13 and 14 are opened, then valve 15, then valve 16, and valve 17.This starts a circulation through the injector and pipe 2 and the tankcontent between the end of the inlet and the end of the outlet pipe 3,and through the latter to the injector. The operator can allow thiscirculation to continue as long as he wishes. When he is ready to obtaina sample, he opens valve 11 and receives the liquid sample in thereceptacle S. To shut the system down, valve 17 is closed first, thenvalve 16, then valve 15, then valves 14 and 13. finally the vent valve 7is opened.

It is noticed that by reason of the circulation accuratelyrepresentative samples are obtained, and there is no waste, and nospilling or surplus which has to be drained to a sewer. And, in practiceliquids of light gravity and normal temperature are easily sampled, asare also liquids of heavy gravity, and high viscosity such as up to 380Furol at F.; and even materials such as molten asphalt are readilyhandled. It is noticed also that a sample can be drawn Without requiringaccess to the sur face of the liquid in the tank.

Other modes of applying the principle of the invention may be employed,change being made as regards the details described, provided thefeatures stated in any of the following claims or the equivalent of suchbe employed.

I therefore particularly point out and distinctly claim as my invention:

1. Apparatus for sampling liquid in a bulk container comprising an inletpipe connected to the side wall of the container at a point spacedbeneath the surface of the liquid therein, an outlet pipe similarlyconnected to the container wall in spaced relation to said inlet pipeand at approximately the same elevation, such pipes extendinghorizontally and being interconnected substantially directly externallyof the container, the pipes and connection thereof forming a normallyclosed system for the withdrawal and substantially immediate return incontinuous fiow of a portion of the liquid in the container, flowinducing means in such system operative to create a considerablepressure differential therein and uninter- -2,s se,oss 7 rupted flow ofthe liquid therethrough, a branch line conw References Cited in the file"of this patent 'nected to an external portion of such system at theinlet UNITED STATES PATENTS slde of said flow Inducing means, and ,valvemeans in a said branch line operative to draw ofi? a sample of the1,860,107 Llen M 1932 liquid without interrupting the continuous flowthereof 5 1,967,428 Quereau July 241 1934 in such system r 2,693,705Casler Nov. 9, 1954 72. Apparatus as set forth in claim 1 characterizedfur- FOREIGN PATENTS ther in that said flow inducing means is operativeto 673,751 Germany Mar 27 1939 inject high velocity air" into the systemc t t

1. APPARATUS FOR SAMPLING LIQUID IN A BULK CONTAINER COMPRISING AN INLETPIPE CONNECTED TO THE SIDE WALL OF THE CONTAINER AT A POINT SPACEDBENEATH THE SURFACE OF THE LIQUID THEREIN, AN OUTLET PIPE SIMILARLYCONNECTED TO THE CONTAINER WALL IN SPACED RELATION TO SAID INLET PIPEAND AT APPROXIMATELY THE SAME ELEVATION, SUCH PIPES EXTENDINGHORIZONTALLY AND BEING INTERCONNECTED SUBSTANTIALLY DIRECTLY EXTERNALLYOF THE CONTAINER, THE PIPES AND CONNECTION THEREOF FORMING A NORMALLYCLOSED SYSTEM FOR THE WITHDRAWAL AND SUBSTANTIALLY IMMEDIATE RETURN INCONTINUOUS FLOW OF A PORTION OF THE LIQUID IN THE CONTAINER, FLOWINDUCING MEANS IN SUCH SYSTEM OPERATIVE TO CREATE A CONSIDERABLEPRESSURE DIFFERENTIAL THEREIN AND UNINTERRUPTED FLOW OF THE LIQUIDTHERETHROUGH, A BRANCH LINE CONNECTED TO AN EXTERNAL PORTION OF SUCHSYSTEM AT THE INLET SIDE OF SAID FLOW INDUCING MEANS, AND VALVE MEANS INSAID BRANCH LINE OPERATIVE TO DRAW OFF A SAMPLE OF THE LIQUID WITHOUTINTERRUPTING THE CONTINUOUS FLOW THEREOF IN SUCH SYSTEM.